The object of the main patent is to provide measures at the transmitting and receiving ends in order to be able to transmit and receive the time critical control signal for the variable dynamic.
The object of the additional patent is to provide measures at the transmitting and receiving ends in order to ensure an exact time correlated association of the time correlated control signal with the relevant signal portion of the radio programme signal.
As was described in the main patent, it is known from the DE-OS 33 11 646 to insert the control signal in the low frequency band region of the useful signal below 100 Hz, which is possible without having any audible influence on the useful signal. However, since the transmission capacity is relatively small in the low frequency edge region, the modulation of the control signal is adversely affected. Furthermore, the low frequency edge region is susceptible to interference, for example with respect to mains hum, so that overall, the transmission of the control signal in this region of the useful signal band is problematic. This appreciation led to the measure of integrating the control signal into the RDS data stream and hence of catering for an assured transmission and evaluation of the control signal.